The invention relates to a seat and backrest arrangement in seat furniture, in particular office chairs, which comprises a seat plate, a seat-plate support and a backrest support and in which the seat-plate, in the region of its front, knee-side edge, is connected moveably to the seat-plate support and, in the region of its rear edge, is connected moveably to the backrest support, the backrest support being coupled displaceably to the seat-plate support.
Seat and backrest arrangements of the generic type are known in particular in office chairs where it is possiblexe2x80x94in order to obtain good seat comfortxe2x80x94not only to adapt the seat height, but also the seat depth and/or the backrest spring system to the specific requirements. Known office chairs which satisfy all demands are often considered to be too expensive in the market place even though the operation and design of these seat furniture items are convenient and satisfy the highest standards of quality.
A work chair or office chair of the generic type having a height-adjustable seat support, a seat plate which can be adjusted in inclination with respect to the said seat support and a backrest support whose inclination with respect to the seat plate is automatically adjusted in accordance with the inclination of the seat plate is disclosed in CH 659 179. In this xe2x80x9csynchronous work chairxe2x80x9d the inclination of the seat plate and the inclination of the backrest support are adjusted as a function of each other and the adjustments are cushioned by a complicated, multipart spring assembly.
This object generally is achieved according to the present invention by a seat and backrest arrangement for seat furniture, in particular office chairs, which comprises: a seat plate, a seat-plate support and a backrest support and in which the seat-plate, in the region of its front, knee-side edge, is connected moveably to the seat-plate support and, in the region of its rear edge, is connected moveably to the backrest support, the backrest support is coupled displaceably to the seat-plate support, and a spring means for cushioning the seat plate and the backrest support is arranged in the region of the front, knee-side edge of the seat plate between the seat plate and seat-plate support. Preferred embodiments and developments of the seat and backrest arrangement according to the invention and of corresponding seat furniture and office chairs emerge from the discussion of the invention below.
Exemplary embodiments of the invention are explained in greater detail belowxe2x80x94without, however, wanting to restrict the scope of the inventionxe2x80x94with reference to schematic drawings.